THE ULTIMATE GUIDE TO ZONE 2 TRAINING
WHAT IS ZONE 2 TRAINING?
Zone 2 training is low-intensity cardiovascular exercise that offers a whole host of incredibly beneficial rewards for the endurance athlete. It is so important that it makes up roughly 70-80% of all training volume for even the world’s fastest athletes. It’s especially vital for the beginner athlete who also needs to give the rest of their body, (think ligaments, tendons and muscles), time to adapt to this new load of repetitive endurance work.
WHAT ARE THE BENEFITS OF ZONE 2 TRAINING?
Training in zone 2 improves heart health, increases endurance and aids better recovery. It is essential for building your “AEROBIC BASE”. It lays the foundation for the more intense training that will come later. It teaches your body to burn fat as a source of energy through the development of your Type 1 slow twitch muscle fibers, which is crucial for long-distance events like marathons or the IRONMAN.
Zone 2 training increases blood capillary and mitochondrial density which improves your ability to produce less lactate and more efficiently clear any lactate that you do produce from the blood. It’s known as the fat burning zone and indeed, often the greatest amount of fat being used for energy (“Fat-Max”) occurs in a Z2 workout. Consistent zone 2 training can therefore also significantly aid sustainable fat loss.
HOW DO I FIND MY ZONE 2?
The intensity of zone 2 training is best controlled using a heart rate monitor (HRM). The gold standard for setting up all of your training zones for use with your HRM is a BLOOD LACTATE test. For zone 2 we generally want lactate levels to be between 0.8-1.9 mmol. This is considered “low” in the world of sports science and is indicative of a metabolic environment where fats can be used for energy. The only way to truly find this is by taking small finger stick blood samples (just like a diabetic does) at various exercise intensities and plotting this data against heartrate and power or pace. From there you can set-up super accurate training zones for zone 2, aerobic and lactate thresholds and VO2 max development.
There are other ways to try to gauge zone 2 but none are as good as lactate. Here they are in order of preference:
LACTATE TEST : the #1 gold standard used by the best of the best. (Watch more HERE)
VO2 TEST : a useful secondary approach but often flawed. (Read why a VO2 test might be a waste of time HERE)
FTP/ FTHR TEST : these are field tests where you work at a maximal sustainable effort for around 20 minutes. You then take your peak power / heartrate and multiply it by 55-75% to set up your zone 2. There are MANY reasons why this is a flawed approach but it is better than ….
HEART RATE FORMULA : here you take 220bpm minus your age and multiply this by 60-70% to get your zone 2 range, or for the “MAF” test you take 180bpm (beats per minute) minus your age as the ceiling of your Zone 2. I will say that I’ve found both of these “guess-timates” to be as much as 30 beats per minute out making them almost pointless.
TALK TEST : some people say that “if you can talk easily” then you are in zone 2 but I find this to be completely false. Many newbies can easily talk and yet have lactate at 3-4 mmol whereas a pro-athlete such as an IRONMAN Triathlete can be working hard and producing significant speeds even at 1.9 mmol lactate! The general effort of this is high even though it is not “metabolically” challenging making talking hard work even though they are going “easy”.
HOW OFTEN SHOULD I DO ZONE 2 EXERCISE?
I am often asked how an athlete should implement zone 2 training into their exercise routine. Thought leaders in the medical community suggest that 150 minutes (2.5hr) per week of zone 2 training is the minimum optimum for health and longevity. For the true endurance athlete doing marathons, Ultras and the IRONMAN, then many more hours per week are required (think 10-15+). Pro-cyclists might do 30 hours of mostly zone 2 riding PER WEEK in a base training phase!
For the beginner, since the intensity and stress on the body is low, I suggest sessions ranging from 45 to 90 minutes. Often this will be walking or walk/jogging. For the advanced athlete we will build up to 4-7 hour sessions for the IRONMAN Triathlete, marathon runner or pro-cyclist.
In general, as a starting point, I’d want to see 3-4 “sessions” per week of zone 2 training for someone serious about making improvements.
HOW WILL I KNOW IF I AM IMPROVING FROM ZONE 2 TRAINING?
Typically, we look for lower lactate at the same power or speed. We also look for a lower heart rate at any given power or pace. This also translates to more power or pace for the same original heart rates over time. So, practically if in month 1 you are at 1.5 mmol lactate and 150 bpm at 200 watts then in month 3 we would expect to see you at 1.2 mmol and 140 bpm at that same power.
As with many things this isn’t always the case!! For example, when you transition from winter to summer training temperatures you might actually have a higher zone 2 heart rate range at the same speed simply due to the increased heat. Similarly, beginner cyclists often don’t have the leg strength required to raise their heart rates to high levels, whereas once they are muscularly stronger they can ride at higher heart-rates and power outputs but with lower lactate.
This is why I always use the set and controlled environment of the sports laboratory to measure metabolic changes and separate field tests to measure the ability to “perform”.
HOW LONG DOES IT TAKE TO SEE IMPROVEMENTS FROM ZONE 2 TRAINING?
How long is a piece of string? If you do a high volume of Z2 work you will see results more rapidly than if you just do short, infrequent sessions. Using periodization to give you key blocks of time in which you focus on a particular aspect of your athletic fitness allows you to make more rapid gains. This is the “base phase” of training where as much as 99% of all training is in zone 2. Here without the stimulus of anaerobic pathways, the body is able to be in “aerobic” mode more constantly and aerobic enzymes can thrive helping adaptations to take hold.
I always say that pro-athletes will see gains every 4-6 weeks and serious age group athletes every 8-10 weeks. For the casual exerciser it can take 3-6 months of consistent training to see substantial improvements in speed while maintaining a Zone 2 heart rate
WHY IS IT SO HARD TO KEEP MY HEART RATE IN ZONE 2?
Many people find it (mentally) difficult to maintain Zone 2 initially and need to slow down significantly to keep their heartrate in zone. To them Zone 2 training feels too easy and therefore many people new to it doubt it’s use. They still think “no pain, no gain” but in this rare case they couldn’t be more incorrect. Zone 2 training is the gift that keeps giving. The more you do, the more gains you get. The easier you train (within reason), the more it works!
WHY IS IT SO IMPORTANT FOR ME TO KEEP MY HEART RATE DOWN FOR ZONE 2 TRAINING TO WORK?
If you allow your heart rate to go above the upper ceiling for your zone 2, then you start to change the fuel being used, with a shift to using sugars instead of fat. You also change the type of muscles being recruited with type 2 fast-twitch fibers starting to be used and therefore a rise in lactate levels. All of this stops the development of your aerobic base. If you “have to” go hard then at least do it at the very end of your session and only sparingly. Similarly do any anaerobic training (such as weight training) AFTER your zone 2 work.
WHAT ARE SOME OF THE COMMON ERRORS PEOPLE MAKE WITH ZONE 2 TRAINING?
The #1 mistake that people make when doing Zone 2 training is going too hard and ignoring their heart rate monitor. It’s quite simple, stay in zone at all costs.
The next zone 2 training mistake is not having the correct zones in the first place because they didn’t get a lactate test and do it properly. Typically, I test my athletes once every 3 months and a lactate test with me is in the range of $350. If the athlete is doing the 150 minute minimum of zone 2 training per week then they will amass 1800 minutes (30 hours) of Z2 training over the 12 week period. That’s $11 per hour for the most accurate training and most of my athletes do significantly more than this making even more cost effective. To put it another way, are you willing to waste 30+ hours of your life training incorrectly and seeing no gains?
Many people skip warm-ups and cooldowns and this is a problem. You want to gradually ease your heart rate up in to zone 2 over at least 5-10 minutes. If you are running start by walking, then walking faster, a gentle jog, a little faster to gradually hit your target zone. Do the reverse to cool-down post workout to better aid recovery bringing your HR slowly towards resting levels before you call it done.
WHAT CAN I DO TO MAXIMIZE THE GAINS FROM ZONE 2 TRAINING?
I suggest that you really focus on controlling stress levels. If you are frequently in a high stress state outside of your training, then you are effectively forcing your body and nervous system into a sugar-burning mode. This is the opposite of an aerobic homeostatic state. Meditation and breathwork are excellent compliments to build your aerobic base.
Food matters too. When building a zone 2 aerobic base you want to create balanced blood sugar with only moderate amounts of carbohydrate in your diet. This is around 40-50% in total and per meal. The balance of 40% carbs, 30% protein and 30% fats is a great ratio to help keep you in a fat-burning state and also supply the optimal balance of energy to perform and recover.
In summary, zone 2 training matters! You can make huge improvements in your performance and health by getting it right. So don’t doubt it and don’t just do it. Instead, “Do it right”!
READ MORE:
THE DO’S AND DON’TS OF HEART RATE TRAINING:
https://www.coachgareth.com/blog/the-dos-and-donts-of-heart-rate-training
KNOW YOUR HEART RATE ZONES:
https://www.coachgareth.com/blog/know-your-zones
WATCH MORE:
